Caption: MODEL RELEASED. Anorexia nervosa. Teenage girl with anorexia nervosa measuring herself with a tape measure in a mirror. The reflection shows her body as she distortedly sees it. Anorexia nervosa, or "slimmer's disease", is an eating disorder in which there is an intense fear of being fat, wilful avoidance of food and severe weight loss. It mostly affects teenage girls and young women. Hospital treatment is often necessary to help sufferers gain weight. Psychotherapy may be needed after reaching a normal weight to try to prevent relapses. Alternatively, the girl may be suffering from bulimia, where the fear of being fat leads to binges of over-eating and self-induced vomiting.